Porifera - “to bear pores”
- level of organization - multicellular w/ specialization, but no tissues
- body symmetry - asymmetrical
- alimentary structures - no extracellular digestion, only phagocytosis
- filter feeds
- reproduction - both sexual/asexual
- asexual reproduction - budding, gemmule release
- sexual reproduction - amoebocytes become gametes
- spicules - crystalline skeletal structures in sponge wall
- spongocoel - central cavity in sponge
- porocytes - forms the pores in sponge
- choanocytes - flagellated cells that draw water through the pores
- not plants due to lack of photosynthesis
- Grantia - simplest sponges
- sessile, filter-feeding
- Spongia - more complex arrangement of chambers than Grantia
Cnidaria - “stinging cells”
- level of organization - diploblastic (2 cell layers), tissues but no organs
- body symmetry - radial symmetry
- alimentary structures - 1-hole sac plan (same hole used as mouth/anus)
- digestion in gastrovascular cavity
- cnidocytes w/ nematocysts to sting prey
- polymorphism - ability to change body shape
- polyp - mostly stationary
- medusa - free-swimming
- Class Hydrozoa - dominant polyp stage
- Portuguese man-of-war (Physalia)
- Class Scyphozoa - dominant medusa stage
- “true jellyfish”
- Class Anthozoa - no medusa stage, usually in colonies
- corals - makes skeleton of calcium carbonate
- Metridium - commone anemone, has tentacles sticking out like hair
- reproduction - both sexual/asexual
- asexual reproduction - budding, fragmentation
- sexual reproduction - medusa release sperm and eggs that become planula larva, which attaches to substrate to become polyp
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